package com.day06;
/*
算法的考察：数组的复制、反转、查找（线性查找、二分法查找）
 */
public class ArrayTest5 {
    public static void main(String[] args){
        String[] arr = new String[]{"JJ","DD","MM","BB","GG","AA"};

        //数组的复制(区别与数组变量的赋值：arr1 = arr)
        String[] arr1 = new String[arr.length];
        for(int i =0;i < arr1.length;i++){
            arr1[i] = arr[i];
        }

        //数组的反转
        //方式一：
     /*   for(int i = 0;i < arr.length / 2;i++){
            String temp = arr[i];
            arr[i] = arr[arr.length - i - 1];
            arr[arr.length - i - 1] = temp;
        }*/

        //方式二：
        for(int i = 0,j = arr.length - 1;i < j;i++,j--){
            String temp = arr[i];
            arr[i] = arr[j];
            arr[j] = temp;
        }

        //遍历
        for(int i = 0;i < arr.length;i++){
            System.out.print(arr[i] + "\t");
        }

        System.out.println();

        //查找（或搜索）
        //线性查找：
        String dest = "BB";
        dest = "CC";
        boolean isFlag = true;
        for(int i = 0;i <arr.length;i++){
            if(dest.equals(arr[i])){
                System.out.println("找到了指定的元素，位置为："+ i);
                isFlag = false;
                break;
            }
        }
        if(isFlag){
            System.out.println("很遗憾，没有找到的啦  ！");
        }
        //二分法查找：(熟悉)
        //前提：所要查找的数组必须有序
        int[] arr2 = new int[]{-98,-34,2,34,54,66,79,105,210,333};

        int dest1 = -34;
        int head = 0;//初始的首索引
        int end = arr2.length - 1;//初始的末索引
        boolean isFlag1 =true;
        while(head <= end){

            int middle = (head + end) / 2;
            if(dest1 == arr2[middle]){
                System.out.println("找到了指定的元素，位置为："+ middle);
                isFlag1 = false;
                break;
            }else if(arr2[middle] > dest1){
                end = middle - 1;
            }else{//arr2[middle] < dest1
                head = middle + 1;
            }
        }
        if(isFlag1){
            System.out.println("很遗憾，没有找到的啦  ！");
        }
    }
}
